From what i found while searching - it won't work, but so far most of the posts and info I found is from 2004-6 though nothing recent...

how far away is the barn?

If you have a router & a cat5 cable you might be able to run the cable to the barn.

My son dug a trench across the driveway and put a network cable out to the garage where he had his computer stuff set up.
At the time we were using an old computer as the sever/router, didn't have dsl or wireless then.
They do have range booster wireless and signal amplifiers.